a. Field of Invention
The invention relates generally to suspension system design for automobiles and the like, and, more particularly to a method and apparatus for finding a coil spring force line range which corresponds to specific damper friction values using a universal spring mechanism, and using the determined force line range in coil spring design methods.
b. Description of Related Art
Conventionally, a suspension coil spring force line position specification is determined from methods using Statics theories and/or mechanical simulation software such as ADAMS. These methods result in a single ideal force line position for a simplified model. Since it is virtually impossible to avoid manufacturing variability with regard to force line position, the force line specification should preferably be a range that takes into account manufacturing variability, and not just an ideal position. Furthermore, ideally the range would be determined experimentally, which would be more accurate than using simple Statics calculations or simulations that require simplified models and assumptions. If the coil spring design needs to limit the damper friction to a certain level from a riding comfort or durability standpoint, an allowable spring force line position range needs to be determined by correlating actual damper friction to force line offset and/or force line inclination. When using simulation software for this purpose, results are invariably dependent on the friction coefficient used for the simulation. Moreover, today's suspension coil spring designs require not only taking into account the one-dimensional force along the coil spring axis, but also require accounting for the exertion of a complex multi-dimensional force and torque field between the spring seats.
Based upon the aforementioned factors and concerns, there remains a need for a method and apparatus for finding a coil spring force line range which is structurally and economically feasible to manufacture and utilize, and a system which efficiently and reliably determines a coil spring force line range for today's complex suspension coil spring designs which are susceptible to one-dimensional forces along the coil spring axis as well as complex multi-dimensional force and torque fields between the spring seats.